Mariners' latest signing reveals their desperation with struggling bullpen

There's a new arm in the Seattle Mariners organization, as the team has agreed to a minor league contract with right-hander Zach Pop. To say he's walking into a volatile situation would be putting it mildly.

Pop's deal with the Mariners was logged on MiLB.com and picked up by Steve Adams of MLB Trade Rumors on Friday, who notes that the 28-year-old is out of options. He had previously been designated for assignment by the Toronto Blue Jays at the end of spring training, and subsequently released in April.

Zach Pop has some upside, but the Mariners' bullpen needs more help than what he is likely to provide

Pop's poor spring training performance (i.e., a 5.40 ERA in seven appearances) wasn't the only storyline surrounding his falling out of favor in Toronto. He had also been dealing with elbow discomfort.

It is unclear what shape Pop's elbow is in now, but it's safe to assume either way that he will not be helping the Mariners especially soon. He'll need to get in some games (presumably with Triple-A Tacoma) and show he's worthy of being added to the big club's bullpen.

Pop does carry some promise in this regard. He's a sinker-slider guy who averaged 96.2 mph on the sinker in 2024, also working in a cutter as the season went along. He had a 55.5 ground-ball percentage, good for the 93rd percentile among all pitchers.

However, there isn't much point in trying to oversell a guy with a career 4.45 ERA and significantly fewer strikeouts (123) than innings pitched (155.2). As relievers go, Pop is basically a warm body until proven otherwise.

This is not to say he can't help the Mariners, as it's indeed impossible to imagine their bullpen being in a worse spot than it is right now. It ranks 17th in the league with a 3.71 ERA, and even pointing that out is a kindness.

Save for the excellent Andrés Muñoz and the surprising Gabe Speier, manager Dan Wilson really doesn't have any relievers he can trust right now. His own problematic management of the bullpen is an issue in its own right, to be sure, but it's not his fault that the pen has the lowest strikeout rate in the American League and about as many hits (77) as innings pitched (77.2).

Troy Taylor's return triggered some hope for Mariners fans, and Matt Brash's will do the same whenever it happens. Even still, it's not too soon for Jerry Dipoto and the front office to get started on a wish list of relievers to pursue in trades, potentially including Ryan Helsley and Kyle Finnegan.

For the time being, they can hope that Pop might be able to help. But given the circumstances, that "might" is doing some really heavy lifting.